When I was about five years old, I learned that it is not wise to
connect a flashlight bulb directly to mains power, even though it is
possible to attach the cord of a 4.5-volt LEGO motor to the bulb with
a piece of tape, and the other end of the wire can be plugged into the
cord of a radio cassette recorder. Luckily, I inserted the plug into
the wall socket last while conducting the experiment. Digital
electronics and embedded systems are easier for me than analog
circuits.